From glass to plasma: in vivo phenolic signatures and metabolic pathways after acute red and white wine intake.

Wine intake may acutely modulate postprandial plasma phenolic metabolism; however, circulating metabolite signatures and associated biotransformation pathways, especially from direct red versus white comparisons using harmonized sampling and analytical workflows, remain incompletely characterized. In a randomized, controlled, four-treatment crossover trial, 10 healthy men consumed a standardized meal with (i) Cabernet Sauvignon red wine (CS), (ii) Robola white wine (R), (iii) an ethanol solution (12.5% v/v, E), or (iv) water (W). Plasma was collected at baseline (-15 min), immediately post-intake (0 min), and repeatedly up to 360 min (12 time points total). Samples were profiled by LC-QTOF-MS in negative ionization mode employing the data-independent acquisition (DIA). A suspect screening workflow was applied using a curated panel of 124 wine phenolics and related metabolites, including parent compounds, major phase II conjugates, and low-molecular-weight phenolic acids associated with microbial catabolism. Multilevel Partial Least Squares-Discriminant Analysis (PLS-DA) leveraged the repeated-measures structure to resolve intervention-related trajectories while reducing baseline between-subject variability. A total of 31 discriminant metabolites (VIP > 1.5) were identified and operationally classified as ethanol-related or wine-related according to their contrast pattern. Both wines induced a structured biphasic postprandial response, with early increases in sulfated and glucuronidated benzoic acids and phenolic alcohols followed by later appearance of γ-valerolactones and phenylpropanoic acids. Red wine intake produced the broadest and most persistent modification in human plasma phenolic metabolite profile, characterized by strong gallate/syringate- related and flavan-3-ol ring-cleavage metabolites. White wine elicited a narrower response dominated by hydroxycinnamate and phenolic-alcohol derived metabolites, followed by valerolactone and phenylpropanoic-acid derivatives. From these time-resolved signatures, four putative phenolic metabolic pathways were proposed, highlighting distinct red- versus white-wine biotransformation patterns.